Dr. Murray Feingold: Genetic testing will change medical care

I recently attended a symposium concerning the effect that new genetic testing can have on the medical care that you receive. This isn’t five or 10 years down the road - it is taking place today.

Just from a blood sample, your approximately 23,000 genes can be tested for gene mutations that cause diseases such as cancer, heart disease, intellectual and physical disabilities, and the list goes on and on. For example, why do some individuals have a strong family history of developing certain types of cancers? Tests called Whole Exome Sequencing (WES) or Whole Genome Sequencing (WGS), can determine if there is a mutation in certain cancer causing genes that can be passed on to family members. These tests can also provide good news by determining that an individual does not have the gene causing cancer.

Then there is personalized medicine.

Why is it that when 100 patients have the same disease and are treated with the same medication, a certain percentage will not respond to the treatment or will develop a serious reaction to the medication? Many times it is due to the individuals genetic makeup. By knowing that patients will not respond to certain medications because of their gene makeup, a more effective drug can be found to successfully treat the illness.

Recent reports have shown that, taking a blood sample from a pregnant woman, a tremendous amount of genetic information can be uncovered about the fetus. Blood from pregnant women contain fetal blood cells. By examining these fetal cells, the genome of the fetus can be ascertained. With this information it can then be determined if the fetus has mutated genes for certain treatable genetic diseases such as breast, ovarian, and thyroid cancers, certain heart diseases and familial high cholesterol.

For some people this is too much information and they may opt out of having such tests. Also, these tests are not a panacea. There can be problems. For example, at times the significance of some of the mutated genes discovered may not be known but may have the potential to be associated with some type of disease. Do you share this uncertain incidental finding with the patient?

We are entering into a new era of medicine–genomic medicine–that is filled with optimism but also has a great deal of uncertainty.

Massachusetts-based Dr. Murray Feingold is the physician in chief of The Feingold Center for Children, medical editor of WBZ-TV and WBZ radio and president of the Genesis Fund. The Genesis Fund is a nonprofit organization that funds the care of children born with birth defects, mental retardation and genetic diseases.